Ingredients in Soap
Soap is a salt of a fatty acid that is used mainly for washing and cleaning. Soap and soap-like materials were made in Ancient Babylon as far back as 2800 BC by boiling ashes with fats. The ashes contain potassium and sodium hydroxide that react with the triglycerides in the fat to form soap. The chemical reaction to produce soap is called "saponification". Potassium salts generaly produce soft soaps, whereas sodium salts produce harder soaps. Most modern soaps contain more ingredients than just soap. Below is the list of ingredients for Irish Spring soap and an explanation of their function.
Ingredients: soap (sodium tallowate, sodium cocoate, and/or sodium palm kernelate), water, hydrogenated tallow acid (skin conditioner), coconut acid, glycerin (skin conditioner), fragrance, sodium chloride, pentasodium pentetate, pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate, titanium dioxide, D&C green No. 8, FD&C Green No. 3.The soap in this product is a mixture of sodium salts of three kinds of fats (tallow, coconut oil, or palm kernel oil). Sodium tallowate is the sodium salt of the fatty acids from tallow (animal fat). Sodium cocoate is a generic name for the sodium salts of a mixture of fatty acids from coconut oil. Sodium palm kernelate is soap made from sodium hydroxide and palm kernel oil. Water, as an ingredient, keeps the soap from becoming too brittle. The hydrogenated tallow acid, coconut acid, and glycerin serve as skin conditioners to keep the skin from becoming too dry after the soap is washed away.
The composition of the fragrance is unspecified. It could be a mixture of many different chemicals. Sodium chloride is ordinary table salt that remains in the product after salt is added to precipitate the soap after saponification. Pentasodium pentetate is a chelating agent used in cosmetics and beauty products that prevents minerals such as calcium and magnesium in hard water from binding to the soap and affecting the foaming and cleaning performance.
Pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate is an antioxidant that inhibits reactions promoted by oxygen that could cause the unsaturated fats in the soap to become rancid. Titanium dioxide is a white pigment that serves to give a lighter color to the soap and modify the color obtained from the use of the green dyes (D&C green No. 8, FD&C Green No. 3).